cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A260461 Numbers k in A096091 such that the nonzero digits of k are not all the same and k/10 is not in the sequence.

Original entry on oeis.org

105, 108, 150, 180, 405, 450, 501, 504, 510, 540, 801, 810, 1002, 1005, 1008, 1020, 1200, 2001, 2004, 2005, 2010, 2040, 2050, 2100, 2400, 2500, 3006, 3060, 3600, 4002, 4005, 4008, 4020, 4080, 4200, 4800, 5001, 5002, 5004, 5020, 5200, 6003, 6030, 6300, 8001
Offset: 1

Views

Author

Jon E. Schoenfield, Jul 26 2015

Keywords

Comments

A096091 contains infinitely many of each of two types of terms (which are not disjoint): (1) terms whose nonzero digits are all the same, and (2) terms that are 10 times another term in A096091. This sequence lists the terms that remain after removal of all terms that match one or both of those two criteria. See comments in A096091.

Crossrefs

A096089 Let f(n) = largest number formed using digits of n, g(n) = smallest number formed using digits of n; then a(n) = floor(f(n)/g(n)).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 1, 2, 2, 3, 3, 4, 4, 4, 10, 1, 1, 1, 1, 2, 2, 2, 2, 3, 10, 2, 1, 1, 1, 1, 1, 1, 2, 2, 10, 2, 1, 1, 1, 1, 1, 1, 1, 1, 10, 3, 2, 1, 1, 1, 1, 1, 1, 1, 10, 3, 2, 1, 1, 1, 1, 1, 1, 1, 10, 4, 2, 1, 1, 1, 1, 1, 1, 1, 10, 4, 2, 2, 1, 1, 1, 1, 1, 1, 10, 4, 3, 2, 1, 1, 1, 1, 1, 1, 100, 10, 17, 23, 29, 34
Offset: 1

Views

Author

Amarnath Murthy, Jun 22 2004

Keywords

Examples

			a(12324) = floor(43221/12234) = 3.
a(1098) = floor(9810/0189) = 51.
		

Crossrefs

Programs

  • Maple
    A096089 := proc(n)
        floor( A004186(n)/A004185(n)) ;
    end proc: # R. J. Mathar, Jul 26 2015
  • PARI
    a(n) = d = digits(n); fromdigits(vecsort(d, , 4)) \ fromdigits(vecsort(d))

Extensions

More terms from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Jul 19 2004
a(1)..a(9) prepended by David A. Corneth, Jan 21 2019

A096090 Index of the first occurrence of n in A096089, or 0 if n never appears.

Original entry on oeis.org

1, 13, 15, 17, 116, 117, 119, 1119, 0, 10, 506, 304, 203, 508, 305, 509, 102, 1012, 307, 205, 308, 2035, 103, 1033, 2056, 207, 1013, 2067, 104, 1044, 209, 1034, 1024, 105, 1055, 1014, 1045, 106, 1035, 2029, 107, 10225, 1046, 1015, 108, 1036, 109, 1078
Offset: 1

Views

Author

Amarnath Murthy, Jun 22 2004

Keywords

Comments

a(9) = 0. For any number with any 0 digits, A096089(n) >= 10. The only number with n digits and no zeros that can be multiplied by 9 to produce a number with the same number of digits is 111...1, so 9 cannot be achieved. A similar argument shows that a(n) = 0 for any n whose leading digit is 9. Note that a(89) = 1011199; probably every number whose leading digit is not 9 does occur in A096089. - Franklin T. Adams-Watters, Jul 19 2006

Examples

			a(7) = 119 as floor[911/119] = floor[7.655462184...] = 7 and 119 is the smallest such number.
		

Crossrefs

Extensions

1119 from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Jul 19 2004, who remarks that a(9) is not known. The terms after a(9) are 10, 506, 304, 203, 508, 305, 509, 102, 1012, 307, 205, 308, 2035, 103, 1033, 2056, 207, 1013, 2067, 104, 1044, 209, 1034, 1024, 105, 1055, 1014, 1045, 106, 1035, 2029, 107, ...
More terms from Franklin T. Adams-Watters, Jul 19 2006

A260462 Numbers k such that the digits of k are in increasing order and k divides (reverse(k) * 10^m) for some sufficiently-large integer m.

Original entry on oeis.org

12, 15, 16, 18, 24, 25, 36, 45, 48, 125, 128, 144, 168, 225, 256, 288, 1125, 1344, 2688, 12288, 111888
Offset: 1

Views

Author

Jon E. Schoenfield, Jul 26 2015

Keywords

Comments

This sequence consists of the set of distinct numbers that result from taking the terms of A260461, sorting the digits of each term in ascending order, and discarding the leading zeros.
(Equivalently, this sequence consists of the set of distinct numbers that result from taking the terms of A096091 whose nonzero digits are not all the same, sorting the digits of each term in ascending order, and discarding the leading zeros.)
Through a(21) = 111888, the digits 7 and 9 do not appear.
After a(21) = 111888, there are no more terms through 10^27. Presumably, the sequence is full. Is there a proof?

Crossrefs

Showing 1-4 of 4 results.